"The transformation begins!" Williams, 26, wrote alongside the Instagram picture. "My first shoot as Pan."

Continued the actress: "Fun fact: I was all ready to cut my hair, then was told by the folks who actually know what they're doing that a wig works better for everybody. So, December 4th, here we come. #wiglife #peterpanlive #nbc"

Williams recently shared another adorable Instagram photo, this one of her from childhood dressed up all in green as – you guessed it – Peter Pan.

"I have wanted to play Peter Pan since I was about 3 years old, so this is a dream come true," Williams stated at the time.

Live TV shouldn't be an issue for Williams, who is the daughter of NBC Nightly News anchorman Brian Williams.